Superconducting transition-edge bolometer arrays for ultra-low power radiometry

A new generation of ultra-low power bolometer arrays is under development for low background infrared astronomy. This paper describes radiometric measurements on such bolometers using a cryogenic blackbody source with accurately calculable throughput. Because of the very long wavelengths used, roughly 100 /spl mu/m-1 /spl mu/m, the absorbed radiant power differs substantially from that in a classical radiometry measurement, where it would be given by the geometric throughput with small "diffraction corrections".